diff options
Diffstat (limited to 'lisp/emacs-lisp/subr-x.el')
| -rw-r--r-- | lisp/emacs-lisp/subr-x.el | 159 |
1 files changed, 158 insertions, 1 deletions
diff --git a/lisp/emacs-lisp/subr-x.el b/lisp/emacs-lisp/subr-x.el index 9529d51e40b..7ad4e9ba2ab 100644 --- a/lisp/emacs-lisp/subr-x.el +++ b/lisp/emacs-lisp/subr-x.el @@ -208,7 +208,9 @@ The variable list SPEC is the same as in `if-let'." (string= string "")) (defsubst string-join (strings &optional separator) - "Join all STRINGS using SEPARATOR." + "Join all STRINGS using SEPARATOR. +Optional argument SEPARATOR must be a string, a vector, or a list of +characters; nil stands for the empty string." (mapconcat #'identity strings separator)) (define-obsolete-function-alias 'string-reverse 'reverse "25.1") @@ -400,6 +402,161 @@ as the new values of the bound variables in the recursive invocation." (cl-labels ((,name ,fargs . ,body)) #',name) . ,aargs))) +(defmacro with-memoization (place &rest code) + "Return the value of CODE and stash it in PLACE. +If PLACE's value is non-nil, then don't bother evaluating CODE +and return the value found in PLACE instead." + (declare (indent 1) (debug (gv-place body))) + (gv-letplace (getter setter) place + `(or ,getter + ,(macroexp-let2 nil val (macroexp-progn code) + `(progn + ,(funcall setter val) + ,val))))) + +;;;###autoload +(defun ensure-empty-lines (&optional lines) + "Ensure that there are LINES number of empty lines before point. +If LINES is nil or omitted, ensure that there is a single empty +line before point. + +If called interactively, LINES is given by the prefix argument. + +If there are more than LINES empty lines before point, the number +of empty lines is reduced to LINES. + +If point is not at the beginning of a line, a newline character +is inserted before adjusting the number of empty lines." + (interactive "p") + (unless (bolp) + (insert "\n")) + (let ((lines (or lines 1)) + (start (save-excursion + (if (re-search-backward "[^\n]" nil t) + (+ (point) 2) + (point-min))))) + (cond + ((> (- (point) start) lines) + (delete-region (point) (- (point) (- (point) start lines)))) + ((< (- (point) start) lines) + (insert (make-string (- lines (- (point) start)) ?\n)))))) + +;;;###autoload +(defun string-pixel-width (string) + "Return the width of STRING in pixels." + (if (zerop (length string)) + 0 + ;; Keeping a work buffer around is more efficient than creating a + ;; new temporary buffer. + (with-current-buffer (get-buffer-create " *string-pixel-width*") + (delete-region (point-min) (point-max)) + (insert string) + (car (buffer-text-pixel-size nil nil t))))) + +;;;###autoload +(defun string-glyph-split (string) + "Split STRING into a list of strings representing separate glyphs. +This takes into account combining characters and grapheme clusters." + (let ((result nil) + (start 0) + comp) + (while (< start (length string)) + (if (setq comp (find-composition-internal + start + ;; Don't search backward in the string for the + ;; start of the composition. + (min (length string) (1+ start)) + string nil)) + (progn + (push (substring string (car comp) (cadr comp)) result) + (setq start (cadr comp))) + (push (substring string start (1+ start)) result) + (setq start (1+ start)))) + (nreverse result))) + +;;;###autoload +(defun add-display-text-property (start end prop value + &optional object) + "Add display property PROP with VALUE to the text from START to END. +If any text in the region has a non-nil `display' property, those +properties are retained. + +If OBJECT is non-nil, it should be a string or a buffer. If nil, +this defaults to the current buffer." + (let ((sub-start start) + (sub-end 0) + disp) + (while (< sub-end end) + (setq sub-end (next-single-property-change sub-start 'display object + (if (stringp object) + (min (length object) end) + (min end (point-max))))) + (if (not (setq disp (get-text-property sub-start 'display object))) + ;; No old properties in this range. + (put-text-property sub-start sub-end 'display (list prop value)) + ;; We have old properties. + (let ((vector nil)) + ;; Make disp into a list. + (setq disp + (cond + ((vectorp disp) + (setq vector t) + (seq-into disp 'list)) + ((not (consp (car disp))) + (list disp)) + (t + disp))) + ;; Remove any old instances. + (when-let ((old (assoc prop disp))) + (setq disp (delete old disp))) + (setq disp (cons (list prop value) disp)) + (when vector + (setq disp (seq-into disp 'vector))) + ;; Finally update the range. + (put-text-property sub-start sub-end 'display disp))) + (setq sub-start sub-end)))) + +;;;###autoload +(defun read-process-name (prompt) + "Query the user for a process and return the process object." + ;; Currently supports only the PROCESS argument. + ;; Must either return a list containing a process, or signal an error. + ;; (Returning `nil' would mean the current buffer's process.) + (unless (fboundp 'process-list) + (error "Asynchronous subprocesses are not supported on this system")) + ;; Local function to return cons of a complete-able name, and the + ;; associated process object, for use with `completing-read'. + (cl-flet ((procitem + (p) (when (process-live-p p) + (let ((pid (process-id p)) + (procname (process-name p)) + (procbuf (process-buffer p))) + (and (eq (process-type p) 'real) + (cons (if procbuf + (format "%s (%s) in buffer %s" + procname pid + (buffer-name procbuf)) + (format "%s (%s)" procname pid)) + p)))))) + ;; Perform `completing-read' for a process. + (let* ((currproc (get-buffer-process (current-buffer))) + (proclist (or (process-list) + (error "No processes found"))) + (collection (delq nil (mapcar #'procitem proclist))) + (selection (completing-read + (format-prompt prompt + (and currproc + (eq (process-type currproc) 'real) + (procitem currproc))) + collection nil :require-match nil nil + (car (seq-find (lambda (proc) + (eq currproc (cdr proc))) + collection)))) + (process (and selection + (cdr (assoc selection collection))))) + (unless process + (error "No process selected")) + process))) (provide 'subr-x) |